Diffusion-resistant organic resin-coupler reaction products for photographic gelatin ayers



United States Patent 3 155,510 DEFUSIGN-RESESTAIQT @RGANEC RESlN -COU- PLlER REACTHQN PRODUCTd FOR PHQTO- GRAl l-HC GELATKN LAYERS Josef Nogradi and Hans Ulrich, Colcgue-Stamrnheim,

Willibald kelz, (lpladen, Walter Piischel, (Iologue- Stamrnheim, and Hans Schellenherger, Leverlrusen, Germany, assignors to Agfa Aktiengesellschaft, Leverkusen, Germany, a corporation of Germany No Drawing. Filed July 19, 1961, Ser. No. 125,079 (Ilaims priority, application Germany July 26, 1960 6 Claims. (Cl. 96-4'4) This invention relates to organic, polymeric compounds in photographic gelatin layers, particularly photographic sflver halide gelatin emulsion layers being fast to diffusion.

Several methods have been described for rendering organic compounds in particular color couplers being incorporated into the silver halide emulsion layers fast to diffusion.

It is, for example, possible to emulsify the solution of hydrophobic color couplers in a high boiling hydrophobic liquid into a gelatin solution. Alternatively, according to another method working in a homogeneous phase, carboxyl or sulfo groups containing color couplers being substituted by long-chain aliphatic radicals which are water-soluble and fast to diffusion due to those substituents are dissolved in the silver halide gelatin emulsion.

Besides the diffusion-resistance of the aforesaid processes organic compounds to be incorporated into the individual layers can be obtained by linle'ng these compounds to more highly polymeric compounds. For example, it has been proposed to link synthetic compounds of high molecular weight, for example polyvinyl alcohol, like an acetal to color couplers and to add these polymers to the emulsion. Furthermore, linkages through carbonamide bridges between coupler and copolymers have already been described. For example, in United States Patent No. 2,297,732 reaction product of a co-polymer of styrene and maleic anhydride with 6-amino-l-naphthol- 3-sulphonic acid is disclosed. Furthermore, polyethylene imines (described for example in United States Patent No. 2,307,399) have been reacted with couplable acid chlorides.

The above-described couplers linked to synthetic polymers have various disadvantages. For example, those containing amino groups tend to fog various emulsions. Others cannot be added to the amulsion in the necessary concentration, because they are not suificiently miscible with the binding agent of the photographic layer e.g. gelatin. Thus only low color intensities are obtained. Many synthetic polymers to which the color couplers are linked, for example copolymers of styrene and maleic anhydride, increase the viscosity of the coating solution to an alarming degree thus complicating the casting procedure. In general this cannot be compensated by adding water, since the drying of the applied layer is then rendered more difficult. Color couplers with long-chain diffusion-inhibiting radicals have similar disadvantages.

It is among the objects of the present invention to provide a novel method for rendering organic compounds incorporated in photographic layers, preferable silver halide gelatin layers, fast to diffusion. Thus providing products with improved chemical and photographic properties.

Other objects will be apparent from the following description:

It has now been found that organic compounds being linked like ester or amide to copolymers of N-vinylpyrrolidone and polymerizable unsaturated acid derivatives and these polymeric reaction products are fast to diffusion in photographic layers. These compounds do ice not cause adverse effects such as fog or increasing of viscosity. The products are sufliciently miscible with photographic gelatin layers. Thus all disadvantages of the conventional difiusion-resistant couplers can be avoided by the compounds according to the invention.

If color couplers are reacted according to the invention and incorporated into a photographic silver halide emulsion, the viscosity of the casting solution is not changed after adding the polymeric coupler. After imagewise exposure and further processing of the material vigorous color gradations with excellent fog values are obtained.

It is particularly advantageous to use copolymers of N vinylpyrrolidone with polymerizable unsaturated acid chlorides, such as methacrylic acid chloride, acrylic acid chloride fumaric acid dichloride, crotom'c acid chloride or polymerizable acid anhydrides, such as maleic acid anhydride.

The ratio between N-vinylpyrrolidone and acid derivatives can be varied, the preferred ratio being from 20 to mol percent of N-vinylpyrrolidone to 80 to 20 mol percent of acid derivative.

The copolymers are preferably prepared in an inert solvent, for example cyclic ethers such as dioxane, tetrahydrofuran, aromatic hydrocarbons such as benzene or toluene, or dialkyl amides such as dimethylformamide. As polymerization catalysts, can be used the peroxides usual for this purpose, azodiisobutyric acid dinitrile and the like. The polymerization temperature depends on the decomposition temperature of the polymerization catalyst being used and lies, in general, between 50 and C.

These copolymers can be linked with all monomeric organic compounds which are to be incorporated in difiusion-resisting manner into photographic layers containing gelatin. More particularly color couplers generally used in color photography coupling components such as described in British Patent No. 861,138, dyestuffs, such as filter dyestuffs, substances absorbing ultraviolet light, organic developing substances, stabilizers and the like can be reacted with the N-vinyl pyrrolidone copolymers.

The polymeric couplers, filter dyestuffs, developers, stabilizers and the like which are obtained can be added alone or in combination with suitable monomeric com pounds to the photographic layers. They can, in general, be used both with photographic black-and-white materials and with color photographic multi-layer materials and may be added both to the silver halide emulsion layer and to one of the photographic auxiliary layers.

The reaction of the copolymers with the monomeric organic compounds in question is effected by known methods and depends on Whether acid chlorides or acid anhydrides have been used for the production of the copolymers, and whether the monomeric organic compound comprises a free hydroxyl group or a primary or secondary amino group. The reaction can be carried out quantitatively with equimolecular quantities of the reactants; it is also possible to use only some of the acid chloride or acid anhydride groups for the acylation and to convert the remainder by hydrolysis into carboxyl groups. Alternatively, the monomeric unsaturated acid derivatives can also be directly reacted with the monomeric organic compound to be incorporated. This product can then be copolymerized with N-vinyl-pyrrolidone.

PREPARATION OF SUITABLE COPOLYMERS (1) 500 cc. of dry dioxane are placed in a 1-liter threenecked flask and g. of methacryl chloride, 100 g. of N-vinyl pyrrolidone and 2 g. of azodiisobutyric acid dinitrile 'are added thereto. Polymerization is carried out under nitrogen at 75 C. for 10 hours. A sample is dried under high vacuum, the polymerization conversion being a 96 percent. Nitrogen analysis shows 47 percent by weight of N-vinyl-pyrrolidone.

(2). As described above 140 g. of methacryl chloride and 160 g. of N-vinylpyrrolidone are polymerized in 500 cc. of dry dimethylformamide.

(3) 200 cc. of dioxane and 60 g. of N-vinylpyrrolidone are placed in a 1-liter stirrer-type vessel. 50 g. of maleic acid anhydride and l g. of azodiisobutyric acid nitrile are dissolved in this mixture. The air above the mixture is displaced with nitrogen and the reaction vessel is heated to 70 C. for eight hours with stirring. After a certain period of time, the polymer starts to precipitate and the mixture is thickened to form a paste which can still just be stirred.

This is suction-filtered, washed with dioxane and dried at 50 C. in vacuo. The yield of polymer is 105 g.:95 percent of the theoretical.

PREPARATION OF THE PRODUCTS FAST TO DIFFUSION (l Color Coupler Forming Yellow Dyestuffs (a) 72 g. of a 30 percent dioxane solution of the acid chloride as described above as copolymer 1 under the heading preparation of the copolymers are added at room temperature to 14 g. of 3-amino benzoylacet-oanisidide suspended in a solution of 8.5 g. of sodium acetate in 100 cc. of glacial acetic acid the mixture being stirred until it dissolves. It is then added with stirring to ten times its volume of water, the precipitate washed with water and then with methanol, dried, and allowed to crystallize from methanol.

The following compounds are reacted in analogous manner:

(b) Benzoylacet-5-amino-2-methoxyanilide,

(c) Benzoylacet-4-amino-Z-methoxyanilide,

(d) 4-aminobenzoylacet-o-ansidide.

(2) Color Coupler Forming Magenta Dyestuffs (a) 22.6 g. of 1-(3-aminophenyl)-3-methylpyrazolone- S-hydrochloride are suspended in the solution of g. of sodium acetate in 150 cc. of glacial acetic acid. The suspension is heated with stirring for 1 hour to 60 to 70 C., cooled to room temperature and, at this temperature, 72 g. of a percent dioxane solution of the acid chloride as described above as copolymer 1 under preparation of the copolymers are introduced dropwise. The mixture is then stirred for 2% hours at to C. and then for 1 hour at 70 C. It is then stirred into 1000 cc. of 2-normal hydrochloric acid, the product suctionfiltered, washed with dilute hydrochloric acid and then with water and dried.

(b) 1 (4'-aminophenyl)-3-methylpyrazolone-S-hydrochloride is reacted in analogous manner.

(0) 17.5 g. 1-phenyl-3-aminopyrazol0ne-5, 21.5 g. of the copolymer of maleic acid anhydride and N-amyl-pyrrolidone described above are heated with stirring in 150 ml. of glacial acetic acid for two hours at 60 C. and thereafter for one hour at 100 C. After cooling the mixture is stirred into 60 ml. of water, filtered, stirred with 200 ml. of 2 normal I-ICl and suction-filtered again. The precipitate is washed with water until the effluent is free of acid. Thereafter the product is added to 300 ml. isopropanol and heated to the boiling point for a short time. 33.5 g. of the condensation product of the starting compounds are obtained.

(d) 14.2 g. of 6-aminoindazolone (free base), 21.5 g. of the copolymer of maleic acid anhydride and N-vinylpyrrolidone described above are heated with stirring in 150 ml. of glacial acetic acid, up to 70 to 80 C. for 2% hours, thereafter up to 100 C. for one hour and finally for another hour up to the boiling point of the solvent. After cooling the resultant mixture is stirred into 600 ml. of water, suction-filtered, rinsed with 200 ml. of 2-normal HCl and filtered again. The precipitate is washed with water until the effluent shows no acidic reaction. After drying the condensation product is shortly boiled two times with 150 ml. of isopropanol. 33 g. of a white product are obtained.

(3) Preparation of Color Couplers Forming Cyan Dyestufis (u) 45 g. of l-naphthol-Z-carboxyl-(N-3'-aminobenzyl- N-3,5-dicarboxyphenyl)-amide are suspended in a solution of 8.5 g. of sodium acetate in 100 cc. of glacial acetic acid described above under preparation of the copolymers and 72 g. of a 30 percent dioxane solution of the copolymer 1 are added at room temperature. The mixture is stirred for 30 minutes at room temperature and then for 30 minutes at 60 C. introduced into ten times the volume of water, the product suction-filtered, again washed with Water, dried and then crystallized from methanol.

In analogous manner, 3-aminophenol or 2-chloro-5- aminophenol may, for example be reacted.

(b) 11 g. of a copolymer of N-vinylpyrrolidone-maleic acid anhydride (molar ratio 55-45) according to copolymer 3 described under preparation of suitable copolymers and 12 g. of 6-chloro-3-aminophenol are boiled under reflux for half an hour in 100 cc. of glacial acetic acid. The mixture is allowed to cool to room temperature, then it is suction-filtered and the residue is triturated twice, using 75 cc. of glacial acetic acid on each occasion, and then it is again suction-filtered. It is then triturated again with 75 cc. of methanol, suction-filtered and dried in vacuo. Yield 15 g.

(4) Preparation of Couplers Forming with the Oxidation Products of Phenylenediamines Colorless Products 20 g. of 1-(3-aminophenyl)-3,4-dimethyI-S-pyrazolone are suspended in a solution of 8.5 g. of sodium acetate in cc. of glacial acetic acid and, at room temperature, 50 g. of a 30 percent dimethylformarnide solution of the copolymer 2 described above under preparation of the copolymers are added. The mixture is stirred for 30 minutes at room temperature and thereafter for another 30 minutes at 60 C. It is incorporated by stirring into ten times the volume of water, suction-filtered, washed with water, dried and then crystallized from methanol.

(5) Preparation of Yellow Filter Dyestufls (a) 10 g. of 4-aminoazobenzene are introduced into the solution of 13.5 g. of sodium acetate in 100 cc. of glacial acetic acid. At room temperature, 36 g. of a 30 percent dioxane solution of the acid chloride described as copolymer 1 under preparation of the copolymers are added dropwise. Thereafter it is heated for 3 /2 hours to 35 to 40 C. and for 15 minutes in a boiling water bath, discharged into 500 cc. of 2-normal hydrochloric acid, suction-filtered, Washed first with dilute hydrochloric acid and then with Water and dried.

In analogous manner are reacted:

(b) 4-amino-2',3-dimethylazobenzene, and

(c) 2-phenyl-(2-azo-4)-naphthyl-1-amine.

EXAMPLE 1 1.5 g. of the polymeric yellow color coupler described under 1(a) are dissolved in 20 cc. of methanol and 20 cc. of 4 percent sodium hydroxide solution and, in admixture with 100 cc. of a conventional gelatino-silver halide emulsion, applied to a subbed cellulose ester support, dried, exposed to light and subjected to a color development.

A yellow dyestulf is obtained upon development.

EXAMPLE 2 A subbed support of polycarbonate on the basis of bis- (di-oxyphenyl-alkane) as described for example in British Patent No. 808,629 is coated with a photographic emulsion layer prepared by adding 1.5 g. of the polymeric magenta coupler 2(a), described above under preparation of difiusion resistant magenta couplers, solved in 20 ml. of methanol and 20 m1. of 4 percent aqueous sodium hydroxide to 100 ml. of a conventional silver halide gelatin emulsion. After exposure and usual color processing After imagewise exposure and conventional color processing using N,N-diethyl-aminoaniline as color-forming developer a cyan image is obtained.

EXAMPLE 41 A support of baryta-coated paper is coated with an ordinary silver chloride emulsion being sensitized to red light and containing 15 g. per kg. emulsion of the polymeric cyan coupler 3(a), described above under preparation of diffusion resistant color couplers. This layer is overcoated with a silver chloride emulsion layer sensitized to green light and containing 15 g. per leg. of the emulsion of the polymeric magenta coupler 1(a), as described above under preparation of diffusion-resistant color coupler. After casting an interlayer, containing colloidal silver as yellow filter layer, the material is over-coated with a third silver halide emulsion layer, containing equal amounts as the layers mentioned above of the polymeric yellow coupler 1(a), as described under preparation of diilusionresistant color couplers.

After exposure through a colored original and conventional color processing using 4-(N-ethyl- I-,8-hydroxy ethyl-amino)aniline as color-forming developer a multicolored image of excellent quality is obtained.

EXAMPLE 5 A multi-layer color-photographic material is prepared according to Example 4 with the exception that between the layer sensitive to red and green light a separation layer is interposed. Said layer is cast from 5 percent aqueous gelatin solution containing per litre 15 g. of the colorless coupler 4 dissolved in 50 ml. of methanol and 20 ml. of 4 percent aqueous sodium hydroxide.

Said colorless couplers react with the oxidation products of a phenylyenediamine developer to form colorless products.

The material is exposed and color processed according to Example 4. The color separation is far better compared with a photographic multi-color material containing no separation layer or only pure gelatin layers as separation layers.

It is to be understood that the above examples are given merely for illustrating the method according to the invention and are not to be construed as limiting the scope of the invention.

It will be clear to those skilled in the art that the practice of the invention lends itself readily to a number of useful modifications in method, materials, etc. For example the binding agents of the photographic layers are not limited to those previously mentioned, because many other water-permeable, film-forming binding agents are suitable such as polyvinylalcohol, carboxymethylcellulose and derivatives, synthetic organic polymers and mixtures thereof with gelatin.

What is claimed is:

1. In a process for the production of a photographic material comprising a support coated with a plurality of emulsion layers, at least one of which is a photosensitive silver halide emulsion layer, the improvement which consists in adding to one of the emulsion layers a reaction product of (i) a color coupler containing a radical of the group consisting of hydroxy and amino radicals which is capable of forming a dye upon development with a primary amine developer, and

(ii) a diffusion-resistant copolymer of N-vinylpyrrolidone and maleic anhydride,

in which reaction product the color coupler and the diffusion-resistant copolymer are linked through a bivalent radical of the group consisting of CO--O and CONH radicals.

2. A process as defined in claim 1 in which the copolymer of N-vinylpyrrolidone and maleic anhydride (ii) from which the reaction product is produced contains between 20 and mols of N-vinylpyrrolidone per mols of copolymer.

3. A process as defined in claim 1 in which the color coupler from which the reaction product is produced is a substance that is capable of forming upon development with a primary amine developer a dye of the group consisting of azomethine, indoaniline and phenazonium dyes.

4. A photographic material comprising a support coated with a plurality of emulsion layers, at least one of which is a photosensitive silver halide emulsion layer and at least one of which contains the reaction product of (i) a color coupler containing a radical of the group consisting of hydroxy and amino radicals which is capable of forming a dye upon development with a primary amine developer, and

(ii) a diffusion-resistant copolymer of N-vinylpyrrolidone and maleic anhydride,

in which reaction product the color coupler and the diffusion-resistant copolymer are linked through a bivalent radical of the group consisting of --COO and -CONH- radicals.

5. A photographic material as defined in claim 4 in which the color coupler from which the reaction product is produced is a substance that is capable of forming upon development with a primary amine developer a dye of the group consisting of azomethine, indoaniline and phenazonium dyes.

6. A photographic material as defined in claim 4 in which the copolymer of N-vinylpyrrolidone and maleic anhydride (ii) from which the reaction product is produced contains between 20 and 80 mols of N-vinylpyrrolidone per 100 mols of copolymer.

References Cited in the file of this patent UNITED STATES PATENTS 2,712,995 Weyde July 12, 1955 2,882,262. Smith et al. Apr. 14, 1959 FOREIGN PATENTS 867,900 Great Britain May 10, 1961 1,233,875 France May 9, 1960 

4. A PHOTOGRAPHIC MATERIAL COMPRISING A SUPPORT COATED WITH A PLURALITY OF EMULSION LAYERS, AT LEAST ONE OF WHICH IS A PHOTOSENSITIVE SILVER HALIDE EMULSION LAYER AND AT LEAST ONE OF WHICH CONTAINS THE REACTION PRODUCT OF (I) A COLOR COUPLER CONTAINING A RADICAL OF THE GROUP CONSISTING OF HYDROXY AND AMINO RADICALS WHICH IS CAPABLE OF FORMING A DYE UPON DEVELOPMENT WITH A PRIMARY AMINE DEVELOPER, AND (II) A DIFUSSION-RESISTANT COPOLYMER OF N-VINYLPYROLIDRONE AND MALEIC ANHYDRIDE, IN WHICH REACTION PRODUCT THE COLOR COUPLER OF THE DIFFUSION-RESISTANT COPOLYMER ARE LINKED THROUGH A BIVALENT RADICAL OF THE GROUP CONSISTING OF -CO-O-AND CO-NH-RADICALS. 